In a fuel circuit inside the engine compartment, it is a known practice to realise a clamp-connection hose comprising a single-layer conduit of thermoplastic material and a rubber conduit having a free end portion that may be connected by means of a clamp to a tubular element inserted by radial interference in the free portion itself and carried for example by a wall of the fuel pump inside the engine compartment.
The rubber conduit is flexible so that it can adapt during assembly to the narrow bulk limits imposed inside the engine compartment and it also presents a second end portion axially opposite the first free portion and suited to be connected to the pipe in thermoplastic material by means of an insert and a second clamp.
In particular, the coupling with radial interference generally used for the connection to a rubber conduit comprises a cylindrical tubular wall coming out of a wall of the pump and a conical ridge or ogive, located on a free edge of the tubular wall and defined by a conical surface diverging towards the wall of the pump.
However, the rubber conduit is expensive, which increases the total price of the pipe, and it may also be difficult to obtain on some markets, which may attain delays in supplies.
EP-A-1055860 discloses a clamp-connection hose comprising a rubber bushing inserted in an end portion of a thermoplastic tube. However, such clamp connection hose is not optimized to guarantee an appropriate extraction load required in some specific applications, e.g. in a fuel circuit of a motor vehicle.